Boolean
public
final
class
Boolean
extends Object
implements
Comparable<Boolean>,
Serializable
java.lang.Object | |
↳ | java.lang.Boolean |
The Boolean class wraps a value of the primitive type
boolean
in an object. An object of type
Boolean
contains a single field whose type is
boolean
.
In addition, this class provides many methods for
converting a boolean
to a String
and a
String
to a boolean
, as well as other
constants and methods useful when dealing with a
boolean
.
Summary
Fields | |
---|---|
public
static
final
Boolean |
FALSE
The |
public
static
final
Boolean |
TRUE
The |
public
static
final
Class<Boolean> |
TYPE
The Class object representing the primitive type boolean. |
Public constructors | |
---|---|
Boolean(boolean value)
This constructor is deprecated.
It is rarely appropriate to use this constructor. The static factory
|
|
Boolean(String s)
This constructor is deprecated.
It is rarely appropriate to use this constructor.
Use |
Public methods | |
---|---|
boolean
|
booleanValue()
Returns the value of this |
static
int
|
compare(boolean x, boolean y)
Compares two |
int
|
compareTo(Boolean b)
Compares this |
boolean
|
equals(Object obj)
Returns |
static
boolean
|
getBoolean(String name)
Returns |
int
|
hashCode()
Returns a hash code for this |
static
int
|
hashCode(boolean value)
Returns a hash code for a |
static
boolean
|
logicalAnd(boolean a, boolean b)
Returns the result of applying the logical AND operator to the
specified |
static
boolean
|
logicalOr(boolean a, boolean b)
Returns the result of applying the logical OR operator to the
specified |
static
boolean
|
logicalXor(boolean a, boolean b)
Returns the result of applying the logical XOR operator to the
specified |
static
boolean
|
parseBoolean(String s)
Parses the string argument as a boolean. |
String
|
toString()
Returns a |
static
String
|
toString(boolean b)
Returns a |
static
Boolean
|
valueOf(String s)
Returns a |
static
Boolean
|
valueOf(boolean b)
Returns a |
Inherited methods | |
---|---|
Fields
FALSE
public static final Boolean FALSE
The Boolean
object corresponding to the primitive
value false
.
TRUE
public static final Boolean TRUE
The Boolean
object corresponding to the primitive
value true
.
TYPE
public static final Class<Boolean> TYPE
The Class object representing the primitive type boolean.
Public constructors
Boolean
public Boolean (boolean value)
This constructor is deprecated.
It is rarely appropriate to use this constructor. The static factory
valueOf(boolean)
is generally a better choice, as it is
likely to yield significantly better space and time performance.
Also consider using the final fields TRUE
and FALSE
if possible.
Allocates a Boolean
object representing the
value
argument.
Parameters | |
---|---|
value |
boolean : the value of the Boolean . |
Boolean
public Boolean (String s)
This constructor is deprecated.
It is rarely appropriate to use this constructor.
Use parseBoolean(java.lang.String)
to convert a string to a
boolean
primitive, or use valueOf(java.lang.String)
to convert a string to a Boolean
object.
Allocates a Boolean
object representing the value
true
if the string argument is not null
and is equal, ignoring case, to the string "true"
.
Otherwise, allocates a Boolean
object representing the
value false
.
Parameters | |
---|---|
s |
String : the string to be converted to a Boolean . |
Public methods
booleanValue
public boolean booleanValue ()
Returns the value of this Boolean
object as a boolean
primitive.
Returns | |
---|---|
boolean |
the primitive boolean value of this object. |
compare
public static int compare (boolean x, boolean y)
Compares two boolean
values.
The value returned is identical to what would be returned by:
Boolean.valueOf(x).compareTo(Boolean.valueOf(y))
Parameters | |
---|---|
x |
boolean : the first boolean to compare |
y |
boolean : the second boolean to compare |
Returns | |
---|---|
int |
the value 0 if x == y ;
a value less than 0 if !x && y ; and
a value greater than 0 if x && !y |
compareTo
public int compareTo (Boolean b)
Compares this Boolean
instance with another.
Parameters | |
---|---|
b |
Boolean : the Boolean instance to be compared |
Returns | |
---|---|
int |
zero if this object represents the same boolean value as the argument; a positive value if this object represents true and the argument represents false; and a negative value if this object represents false and the argument represents true |
Throws | |
---|---|
NullPointerException |
if the argument is null |
See also:
equals
public boolean equals (Object obj)
Returns true
if and only if the argument is not
null
and is a Boolean
object that
represents the same boolean
value as this object.
Parameters | |
---|---|
obj |
Object : the object to compare with. |
Returns | |
---|---|
boolean |
true if the Boolean objects represent the
same value; false otherwise. |
getBoolean
public static boolean getBoolean (String name)
Returns true
if and only if the system property named
by the argument exists and is equal to, ignoring case, the
string "true"
.
A system property is accessible through getProperty
, a
method defined by the System
class.
If there is no
property with the specified name, or if the specified name is
empty or null, then false
is returned.
Parameters | |
---|---|
name |
String : the system property name. |
Returns | |
---|---|
boolean |
the boolean value of the system property. |
Throws | |
---|---|
SecurityException |
for the same reasons as
System.getProperty |
hashCode
public int hashCode ()
Returns a hash code for this Boolean
object.
Returns | |
---|---|
int |
the integer 1231 if this object represents
true ; returns the integer 1237 if this
object represents false . |
hashCode
public static int hashCode (boolean value)
Returns a hash code for a boolean
value; compatible with
Boolean.hashCode()
.
Parameters | |
---|---|
value |
boolean : the value to hash |
Returns | |
---|---|
int |
a hash code value for a boolean value. |
logicalAnd
public static boolean logicalAnd (boolean a, boolean b)
Returns the result of applying the logical AND operator to the
specified boolean
operands.
Parameters | |
---|---|
a |
boolean : the first operand |
b |
boolean : the second operand |
Returns | |
---|---|
boolean |
the logical AND of a and b |
See also:
logicalOr
public static boolean logicalOr (boolean a, boolean b)
Returns the result of applying the logical OR operator to the
specified boolean
operands.
Parameters | |
---|---|
a |
boolean : the first operand |
b |
boolean : the second operand |
Returns | |
---|---|
boolean |
the logical OR of a and b |
See also:
logicalXor
public static boolean logicalXor (boolean a, boolean b)
Returns the result of applying the logical XOR operator to the
specified boolean
operands.
Parameters | |
---|---|
a |
boolean : the first operand |
b |
boolean : the second operand |
Returns | |
---|---|
boolean |
the logical XOR of a and b |
See also:
parseBoolean
public static boolean parseBoolean (String s)
Parses the string argument as a boolean. The boolean
returned represents the value true
if the string argument
is not null
and is equal, ignoring case, to the string
"true"
.
Otherwise, a false value is returned, including for a null
argument.
Example: Boolean.parseBoolean("True")
returns true
.
Example: Boolean.parseBoolean("yes")
returns false
.
Parameters | |
---|---|
s |
String : the String containing the boolean
representation to be parsed |
Returns | |
---|---|
boolean |
the boolean represented by the string argument |
toString
public String toString ()
Returns a String
object representing this Boolean's
value. If this object represents the value true
,
a string equal to "true"
is returned. Otherwise, a
string equal to "false"
is returned.
Returns | |
---|---|
String |
a string representation of this object. |
toString
public static String toString (boolean b)
Returns a String
object representing the specified
boolean. If the specified boolean is true
, then
the string "true"
will be returned, otherwise the
string "false"
will be returned.
Parameters | |
---|---|
b |
boolean : the boolean to be converted |
Returns | |
---|---|
String |
the string representation of the specified boolean |
valueOf
public static Boolean valueOf (String s)
Returns a Boolean
with a value represented by the
specified string. The Boolean
returned represents a
true value if the string argument is not null
and is equal, ignoring case, to the string "true"
.
Otherwise, a false value is returned, including for a null
argument.
Parameters | |
---|---|
s |
String : a string. |
Returns | |
---|---|
Boolean |
the Boolean value represented by the string. |
valueOf
public static Boolean valueOf (boolean b)
Returns a Boolean
instance representing the specified
boolean
value. If the specified boolean
value
is true
, this method returns Boolean.TRUE
;
if it is false
, this method returns Boolean.FALSE
.
If a new Boolean
instance is not required, this method
should generally be used in preference to the constructor
Boolean(boolean)
, as this method is likely to yield
significantly better space and time performance.
Parameters | |
---|---|
b |
boolean : a boolean value. |
Returns | |
---|---|
Boolean |
a Boolean instance representing b . |